1. Field of the Invention
The present invention relates to mobile communications and, more particularly, to reporting of mobile station location.
2. Description of Related Art
Cellular wireless is an increasingly popular means of personal communication in the modern world. People are using cellular wireless networks for the exchange of voice and data over cellular telephones, Personal Digital Assistants (“PDAs”), cellular telephone modems, and other devices. In principle, a user can seek information over the Internet or call anyone over a Public Switched Telephone Network (“PSTN”) from any place inside the coverage area of the cellular wireless network.
An important feature of contemporary cellular wireless networks is an ability to locate the geographical position of a mobile station. Such a feature was developed initially to assist emergency services in locating a mobile station. For example, in the United States, the Federal Communications Commission (“FCC”) has mandated the implementation of “Enhanced 911” (“E911”) services.
The E911 mandate was divided into two phases. According to Phase 1, the location must be identified with an accuracy of at least cell and sector. As this information is typically maintained by a wireless cellular carrier in a subscriber's home location register (“HLR”), Phase 1 presents little technical challenge. According to Phase 2, the location must be provided with an accuracy of at least 100 meters (or 50 meters for handset-originated methods such as GPS), which is far more granular than the cell and sector information maintained in the HLR. In response, the Telecommunications Industry Association (TIA) has proposed a new standard for “Enhanced Wireless 9-1-1, Phase 2,” now entitled “Wireless Enhanced Emergency Services” or “TIA/EIA/IS-J-STD-036” (J-STD-036), the entirety of which is hereby incorporated by reference.
In order to achieve the accuracy specified by Phase 2, a cellular wireless network may employ a special position determining entity (“PDE”) and techniques. Alternatively, a mobile station itself may employ a position determining system such as global position satellite (GPS) system and may relay its position to the network, for reference by the emergency services. The emergency services may then use the position of the mobile station to help assist a user of the mobile station.